<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>css3 box属性认知</title>
    <style>
        .pardiv{
            width:300px;
            height:300px;
            display: -webkit-box;
            -webkit-box-align: center;
            -webkit-box-pack: center;
            border:1px solid #333;
        }
        .childiv{
            width: 50px;
            height: 50px;
            border:1px solid #333;
            margin-right:10px
        }
        。childiv2{
            -moz-box-ordinal-group:1  
        }
    </style>
    <!---  -webkit-box-direction:reverse;反向排列
        -webkit-box-align: start|end|center|baseline|stretch;  
        -webkit-box-flex: 1.0|2.0;子元素所占空间比例大小
        -moz-box-ordinal-group:1|2|3  // 排序位置
        -->
</head>
<body>
    <div class="pardiv">
        <div class="childiv">1</div>
        <div class="childiv childiv2">2</div>
        <div class="childiv">3</div>
    </div>
</body>
</html>